How to choose a budget of 100 yuan? Guide to Choosing a Camera for Creating a 30cm Small Fish Tank w

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Abstract: Want to use a low-power, RTSP-compatible camera to create a 24/7 live stream for your small fish tank? Based on practical experience and pitfalls, this article analyzes the key points for purchasing a camera capable of clearly filming a 30cm small fish tank within a budget of around 200 RMB, particularly focusing on the "focus" issue that is most easily overlooked.

Keywords: Fish Tank Camera, Live Streaming, RTSP Protocol, Smart Home, IP Camera, Focal Length Selection, Manual Focus, ZWPlayer

1. Clarifying Requirements: We're Not Just Looking for a Camera

To create a fish tank live stream, the core requirements are: Clear Imaging: The primary goal is to clearly capture details within a 30cm small fish tank (fish, aquatic plants, landscaping). RTSP Protocol Support: This is the technical key. The RTSP protocol allows RTSP web players like ZWPlayer to directly pull video streams, enabling seamless web live stream embedding. Low Power Consumption: Requires 7x24 uninterrupted operation; low power means more stable and energy-efficient operation. Affordable: Budget controlled around 200 RMB. As a personal hobby project, costs need to be strictly controlled.

Common household surveillance cameras on the market are often designed for monitoring scenes several meters to tens of meters away. Directly using them for fish tanks often leads to "compatibility issues".

2. Core Parameter Analysis: Why Focal Length is Just the First Step?

1. Focal Length: Determines Your "Field of View" Focal length is the first threshold for selection. Simply put:

Small focal length (e.g., 2.8mm): Wide field of view, suitable for shooting close-range, large-area scenes. For small fish tanks, 2.8mm or 4mm focal length is the first choice, ensuring the entire tank fits in the frame. Large focal length (e.g., 6mm and above): Narrow field of view, suitable for shooting distant specific targets. Using this for fish tanks would be like "looking at a leopard through a tube," only seeing a partial view.

Conclusion: For small fish tank purchases, prioritize cameras with 2.8mm or 4mm focal length. Below is a comparison image of long vs. short focal length fields of view:

2. Focus Function: The Key to Determining Whether the Image is "Clear"! (Easy to Overlook) This is the core reminder of this article. Many entry-level cameras are fixed-focus cameras with a fixed focal plane, typically optimized for distances of several meters to ten meters.

The Problem: According to the physical imaging formula 1/f = 1/u + 1/v, when focal length f is fixed and object distance u (distance from fish tank to lens, e.g., 10cm-30cm) changes dramatically, image distance v also needs corresponding adjustment for clear imaging. Fixed-focus cameras cannot adjust v, resulting in an out-of-focus state when shooting close-range fish tanks, appearing completely blurry.

Personal Pitfall: Initially chose the popular TP-LINK TL-IPC341P (2.8mm focal length) model, but because it has a fixed focal plane, shooting fish tanks within 30cm was very blurry and couldn't meet requirements.

Solution: Choose cameras that support manual focus.

As shown in the diagram, this type of camera lens can be fine-tuned by rotation, thereby changing image distance v, allowing close-range objects to also fall clearly on the focal plane.

3. Buying Guide and Practical Tips

Based on the above analysis, your shopping filter criteria should be very clear:

Step 1: Search Keywords. Use "2.8mm IP camera", "4mm surveillance camera" on e-commerce platforms. Step 2: Core Screening. Carefully check product details pages or consult customer service directly to confirm two points:

Does it support RTSP protocol? (Usually listed in "Advanced Features" or "Protocol Support" in details) Does it support manual focus? (Preferably find product diagrams showing rotatable lenses like above)

Step 3: Price Screening. Set price range to 100-200 RMB. This price range has many "generic" products meeting the first two conditions, offering high value.

Final Solution: Found a 3.6mm camera with manual focus function on Taobao, cheaper than the TL-IPC341P that caused the pitfall. After fine-tuning focus by rotating the lens, the fish tank interior is very clear.

4. Conclusion

Selecting a live streaming camera for a small fish tank is not something that can be solved by "just buying any surveillance camera." Within a limited budget, you need to avoid the "fixed-focus camera" trap. Remember this formula: Small focal length (2.8mm/4mm) + Manual focus function + RTSP protocol support = Perfect fish tank live streaming camera. After choosing the right camera, paired with a web player like ZWPlayer, you can easily build a stable, clear 24/7 fish tank live stream to share your underwater world with friends.